Top PDF Investigation of strong earthquake ground motion

Investigation of strong earthquake ground motion

Investigation of strong earthquake ground motion

v TABLE OF CONTENTS PART I II TITLE PAGE INTRODUCTION 1 PATTERN OF ENERGY RELEASE DURING THE IMPERIAL VALLEY, CALIFORNIA EARTHQUAKE OF 1940 3 RELATIVT!: AMPLITUDES AND SPECTRAL PROPERTIE[r]

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Stochastic ground motion simulations for the 2016 Kumamoto, Japan, earthquake

Stochastic ground motion simulations for the 2016 Kumamoto, Japan, earthquake

Ground-motion data and site information were obtained from the KiK-net at http://www.kyoshin.bosai.go.jp/, the NIED strong-motion seismograph net- works, last accessed May 1, 2016. All the figures in this paper were prepared using Generic Mapping Tools (Wessel et al. 2013). The authors would like to thank Dr. R. Wang for providing the baseline correction code. We appreciate the helpful discussions with Z. Jiang, Z. Liu, S. Zhou, W. Wang and W. Feng. In addition, the authors thank Prof. Martha Savage (the editor) and two anonymous reviewers for their helpful comments on the draft manuscript. Also, this work was financially supported by National Science Foundation of China (41474002), Grant-in-Aid for challenging Exploratory Research (Grant No. 15K12483, G. Chen) from Japan Society for the Promotion of Science and Kyushu University Interdisciplinary Programs in Education and Projects in Research Development. These financial supports are gratefully acknowledged.
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Fuzzy logic-based attenuation relationships of strong motion earthquake records

Fuzzy logic-based attenuation relationships of strong motion earthquake records

Fuzzy logic techniques have been widely used in civil and earthquake engineering applications in the past four decades. However, no thorough research studies were conducted to use them for deriving attenuation relationships for peak ground accelerations (PGA). This paper is an attempt to fill this gap by employing a fuzzy approach with fuzzy sets for earthquake magnitude and distance from source with the objective of proposing new ground motion attenuation models. Recent earthquake records from USA and Taiwan with magnitudes 5 or greater were used; and consisted of horizontal peak ground acceleration recorded on three different site conditions: rock, soil and soft soil. The use of Fuzzy models to quantify ground motion records, which are typically characterized by a high level of uncertainty, leads to a rational analytical tool capable of predicting accurate results. Testing of the fuzzy model with an independent data set confirmed its accuracy in predicting PGA values.
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Examination of source model construction methodology for strong ground motion simulation of multi segment rupture during 1891 Nobi earthquake

Examination of source model construction methodology for strong ground motion simulation of multi segment rupture during 1891 Nobi earthquake

For multi-segment ruptures, researchers have discussed whether or not the repetition of the same dislocation rup- ture characterizes each of the segments of a long active-fault zone (e.g., Sieh, 1996; McGill and Rubin, 1999; Kaneda and Okada, 2008). The repetition of the same dislocation rupture for each segment is not considered in existing con- struction methodologies for the characterized source model for strong ground-motion prediction, such as the methodol- ogy developed by HERP (2008b). However, several active- fault studies have supported the concept of repetition of a similar slip along a segment (e.g., Sieh et al., 1996; Kondo et al., 2005). Therefore, in the construction methodol- ogy we need to consider the behavior of each segment in- volved in a multi-segment rupture. Here, we consider be- havioral segments that are bounded by changes in the slip rates, recurrence intervals, elapsed times, sense of displace- ment, creeping versus locked behavior, and fault complexity (McCalpin, 1996).
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Source model for strong ground motion generation in the frequency range 0 1–10 Hz during the 2011 Tohoku earthquake

Source model for strong ground motion generation in the frequency range 0 1–10 Hz during the 2011 Tohoku earthquake

The source model of the 2011 Tohoku earthquake, which is composed of four strong motion generation areas (SMGAs), is estimated based on the broadband strong ground motion simulations in the frequency range 0.1–10 Hz using the empirical Green’s function method. Two strong motion generation areas are identified in the Miyagi- oki region west of the hypocenter. Another two strong motion generation areas are located in the Fukushima-oki region southwest of the hypocenter. The strong ground motions in the frequency range 0.1–10 Hz along the Pacific coast are mainly controlled by these SMGAs. All the strong motion generation areas exist in the deeper portion of the source fault plane. The stress drops of the four SMGAs range from 6.6 to 27.8 MPa, which are similar to estimations for past M 7-class events occurring in this region. Compared with the slip models and aftershock distributions of past interplate earthquakes in the Miyagi-oki and Fukushima-oki regions since the 1930s, the SMGAs of the 2011 Tohoku earthquake spatially correspond to the asperities of M 7-class events in 1930s. In terms of broadband strong ground motions, the 2011 Tohoku earthquake is not only a tsunamigenic event with a huge coseismic slip near the trench but is also a complex event simultaneously rupturing pre-existing asperities.
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On the recovery of peak ground velocity and peak ground displacement from strong-motion records

On the recovery of peak ground velocity and peak ground displacement from strong-motion records

displacement response spectra of a record corrected using the extended Graizer algorithm is useful in deciding whether the correction achieved is reasonable. The correction procedure can be as- sumed to be adequate if the periods at which SV is roughly equal to PGV and SD roughly equals PGD is less than or equal to the rupture duration of the earthquake and that for longer periods the spectral ordinates are constant. If however, there is significant energy within the time-history for periods greater than the rupture duration, i.e. the SV and/or SD are not constant for periods greater than rupture duration, then this would mean that the correction made using the extended Graizer technique is probably incorrect.
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Stochastic ground motion simulation of the 2016 Meinong, Taiwan earthquake

Stochastic ground motion simulation of the 2016 Meinong, Taiwan earthquake

surface-to-downhole station pairs (Wen et al. 1994, 1995; Beresnev et  al. 1995a, b). They indicated that, during nonlinear soil behavior, the spectral ratio from strong motions has lower predominant frequency and amplifi- cation than the spectral ratio from weak motions. After the earthquakes in 1985 in Michoacan, Mexico, and in 1989 in Loma Prieta, California, several large earth- quakes have been recorded by modern digital surface and vertical arrays. Observations around the world estab- lished direct evidence of the significance of nonlinear site effects (Beresnev and Wen 1996). Wen et al. (2006) used the horizontal-to-vertical spectral ratio (HVSR) method to analyze the Large-Scale Seismic Test (LSST) array in Lotung, Taiwan, and found that the HVSR method can be used to identify nonlinear site responses. Noguchi and Sasatani (2008, 2011) proposed a new quantitative index to measure the degree of nonlinear site response (DNL). The DNL showed positive correlations with the observed horizontal peak ground acceleration (PGA) on the ground surface and with V S30 .
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Selection of ground motion prediction equations for the global earthquake model

Selection of ground motion prediction equations for the global earthquake model

distances (>100 km) are not substantially reduced from those closer to the source. This behavior was considered physically unlikely by some members of the Task 3 expert panel, who therefore recommended that the model be rejected. Nevertheless, it was decided to retain this model since the slow decay rate has been observed in some earthquakes (e.g., Maule Chile; Boroschek et al., 2012) and this model has been shown to work well in model-data comparisons for smaller magnitude events as well (e.g., study A in Table 2). Moreover, since variable distance attenuation rates are observed across global data sets for interface subduction zone earthquakes, and the AEA12 and ZEA06 models have relatively fast distance attenuation rates, use of the AB03 model was considered desirable to capture this important source of epistemic uncertainty. Nonetheless, we never reached full consensus on the selection of this particular model and no strong alternative model emerged during discussions.
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Calibrating the backbone approach for the development of earthquake ground motion models

Calibrating the backbone approach for the development of earthquake ground motion models

One of the principal challenges in applying the backbone approach is its calibration so that the branches of the ground-motion logic tree capture the appropriate level of epistemic uncertainty. This is particularly difficult for regions with limited strong-motion data, which are generally areas of lower seismicity. In this article, I summarize previous uses of the backbone approach in the literature before investigating calibration using the stochastic method, which is particularly useful when there are few or no local strong-motion records. I show that the scaling factors developed from the stochastic models roughly imply the expected variations in epistemic uncertainty given the amount of data available from different tectonic regimes.
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Strong ground motion in the Kathmandu Valley during the 2015 Gorkha, Nepal, earthquake

Strong ground motion in the Kathmandu Valley during the 2015 Gorkha, Nepal, earthquake

rock site KTP. In contrast, the horizontal ground veloci- ties at the sedimentary sites had long duration with con- spicuous long-period oscillations; we pointed out these features for the accelerograms discussed in the previous section (Fig. 2). Assuming that the KTP (rock site) ground velocities represent incoming wave fields into the Kathmandu Valley, we can consider the large ground velocities at the sedimentary sites in Fig. 3 to be the long-period (3–5 s) valley response. Here, we perform a simple examination of the long-period valley response in the frequency domain. The upper panel in Fig. 4 displays the Fourier amplitude spectra of the ground velocities shown in Fig. 3; we classified the spectra into three components in order to compare one another’s spectral shape for a given component. The lower panel in Fig. 4 shows the Fourier amplitude spectral ratios of the sedimentary site spectra to the rock site spectrum for each component; these figures correspond to the valley response in the frequency domain for a given site. From examination of Figs. 3 and 4, we found that the long- period valley response had the following features: (1) the horizontal valley response was characterized by large amplification (about 10) and prolonged oscillations, (2) the predominant period and envelope shape of the horizontal oscillation differed not only from site to site but also between the NS and EW components at a given site, and (3) the vertical valley response had no amplifi- cation and no prolonged oscillations. These features demonstrate that the long-period valley response of the Kathmandu Valley is considerably complicated, because they cannot be understood with one-dimensional seismic wave amplification. Previous studies indicated an uneven basement topography of the valley with many undula- tions (Moribayashi and Maruo 1980; Paudyal et al. 2013) which may result in a complicated response. In order to understand the factors involved in the observed long- period valley response of the Kathmandu Valley, we will have to clarify the three-dimensional underground struc- ture of the valley in addition to the dense strong-motion observations in and around the valley.
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Strong Ground Motion Eects on Seismic Response Reduction by TLCDs

Strong Ground Motion Eects on Seismic Response Reduction by TLCDs

Because earthquake records have dierent peak ground motions, they cannot be used on an absolute basis to show the eects of dierent parameters. So, the records were scaled to a peak ground acceleration of 0.35 g before they were imposed to the structure model. In order to get a better view of the frequency content of the records, the Fourier spectra of all records were also computed. This allowed an investigation of the eects of the frequency content of excitation on TLCD performance. Additionally, the response spectra of records were computed, because the peaks and valleys in the response spectrum of the records aect the response of the structure and, subsequently, the performance of TLCD.
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The potential of high rate GPS for strong ground motion assessment

The potential of high rate GPS for strong ground motion assessment

Given current processing techniques, the standard GPS sam- pling rate of 1 Hz is sufficient for far-field recordings of earthquakes. Higher sampling rates (5 Hz or more) would, however, be required to record all possible on-scale energy for near-field records (i.e., for stations located within a 10- km epicentral distance for magnitude 6 events and within 30 km for magnitude 7) and for megathrust earthquakes at larger distances. This higher sampling rate is particularly crucial to retrieve more accurate estimates of PGV in the near field. We find that using sampling rates above 5 Hz does not provide any additional information for earthquake ground- motion recordings except at very short distances (below 5 km). This is true even using more accurate postprocessed methods. PGV values (especially those extracted using post- processed data) can complement PGV datasets from seismo-
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Effect of Irregular  Topography on Strong Ground Motion Amplification (K190)

Effect of Irregular Topography on Strong Ground Motion Amplification (K190)

2. Ishida, H., Sasaki, T., Niwa, M., Kitagawa, Y. and Kashima, T., “Amplification characteristics of surface layers obtained from earthquake observation records of vertical instrument arrays at Kushiro local meteorological observatory” (in Japanese), Journal of Structural and Construction Engineering, AIJ, No. 490, 1996, pp.91-100. 3. Paolucci, R., “Amplification of earthquake ground motion by steep topographic irregularities”, Earthquake

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Stochastic Study of the Effect of Strong Ground Motion Variables on Input Energy

Stochastic Study of the Effect of Strong Ground Motion Variables on Input Energy

Uang and Bertero [13] proposed two procedures for computing the earthquake input energy: one based on absolute motion and the other on relative motion. The dierence between the two procedures is less impor- tant in damage assessment, and the damage potential of structures is independent of the approach used. Bruneau and Wang [14], and Chopra [15] believe that the input energy, in terms of relative motion, is more meaningful than the input energy in terms of absolute motion, since internal forces within structures are computed using relative displacements and velocities. Therefore, the procedure based on relative displace- ment is used in this study. Consider the equation of motion of a proportionally damped linear elastic Multi- Degree-Of-Freedom (MDOF) system subjected to uni- directional horizontal ground acceleration, u g (t):
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Analysis of the strong motion records obtained from the 2007 Niigataken Chuetsu-oki earthquake and determination of the design basis ground motions at the Kashiwazaki Kariwa Nuclear Power Plant (Part1: Outline of the strong motion records and estimation o

Analysis of the strong motion records obtained from the 2007 Niigataken Chuetsu-oki earthquake and determination of the design basis ground motions at the Kashiwazaki Kariwa Nuclear Power Plant (Part1: Outline of the strong motion records and estimation o

The Niigataken Chuetsu-Oki Earthquake occurred on July 16, 2007, with the epicenter in the Sea of Japan off the Niigata Prefecture. The magnitude of the event was Mj6.8 determined by Japan Meteorological Agency. With this earthquake, strong ground motion was observed at the Kashiwazaki Kariwa Nuclear Power Plant of the Tokyo Electric Power Company, which was larger than the average ground motion of Mj6.8 supposed from the attenuation relationship of Noda et al. (2002). In addition, in the Kashiwazaki Kariwa Nuclear Power Plant, there were large variations in recorded ground motion at different parts of the observation point, especially records in the southern part of the site were larger than these in the northern part of the site.
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Peak ground motion predictions with empirical site factors using Taiwan Strong Motion Network recordings

Peak ground motion predictions with empirical site factors using Taiwan Strong Motion Network recordings

Liu and Tsai (2005) derived new ground motion predic- tion equations for crustal earthquakes in Taiwan using a tra- ditional regression method. The earthquake magnitude and hypocentral distance are the only two parameters during re- gressions for deriving their attenuation relationships. How- ever, another popular approach to predicting the ground mo- tion requires a source model and a predictive relationship which allows the estimation of a specific ground motion pa- rameter as a function of magnitude, distance, source param- eters, and frequency. The predictive relationship is char- acterized by a geometric spreading function, a frequency- dependent crustal Q function, and a function describing the effective duration of the ground motion. Following the ap- proaches described in the papers of Raoof et al. (1999) and Malagnini et al. (2000), the regional attenuation of seismic waves in Taiwan is firstly investigated in this study. The predictive relationships here were built up by a great num- ber of strong motion data collected by the Taiwan Strong Motion Network (TSMN) operated by the Central Weather Bureau (CWB) under the Taiwan Strong Motion Instrumen- tation Program (Shin, 1993). Essentially, the advantage of their method over the classical regression analysis is to take into account the duration parameter as a function of fre- quency and distance, which is more effective in structural engineering applications.
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A note on the use of strong-motion data from small magnitude earthquakes for empirical ground motion estimation

A note on the use of strong-motion data from small magnitude earthquakes for empirical ground motion estimation

classified using other methods. For example, the faulting mechanism of aftershocks is often assumed to be the same as that for the mainshock. For some earthquakes, however, this is not always true. For example, Ouyed et al. (1983) compute well-constrained focal mechanisms for 81 aftershocks of the thrust faulting 10/10/1980 El Asnam (Algeria) earthquake using an array of 28 portable seismic stations. They find that aftershocks mainly displayed thrust mechanisms but a significant proportion showed strike-slip mechanisms and two aftershocks even had normal faulting. Lyon-Caen et al. (1988) compute focal mechanisms of 133 aftershocks of the normal faulting 13/9/1986 Kalamata earthquake using records from 16 temporary stations. They find that although most aftershocks displayed normal mechanisms, some showed strike-slip faulting and some aftershocks in the footwall had reverse mechanisms. Consequently, if records from aftershocks with no published focal mechanisms, but which are assumed to have the same mechanism as the main shock, are used, this can increase the uncertainty in the computation of style-of-faulting coefficients.
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Strong motion PGA prediction for southwestern China from small earthquake records

Strong motion PGA prediction for southwestern China from small earthquake records

Ground motion prediction equation (GMPE) is a vital field in the research of engineering seismology. A great number of research results have been published, and most of them are empirical, such as those for the western United States by the Next Generation Attenuation (NGA) project (Power et al., 2008; Bozorgnia et al., 2012; Boore et al., 2014) and those for Japan (Si and Midorikawa, 2000; Kanno, 2006). Empiri- cal GMPEs are developed, mainly based on plenty of strong

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Broadband ground motion simulation of the 2010 2011 Canterbury earthquake sequence

Broadband ground motion simulation of the 2010 2011 Canterbury earthquake sequence

We use the hybrid ground motion simulation approach of Graves and Pitarka (2010, 2015), which computes the low- and high-frequency wavefields separately, then combines the two motions to form broadband seismograms. The chosen transition frequency is 1Hz, up to which the low-frequency part is well resolved. At low frequencies (f<1Hz herein), the principal features of strong ground motions are modeled by solving a 3D heterogeneous viscoelastic wave propagation problem based on a staggered-grid finite difference scheme with fourth-order spatial and second-order temporal accuracies. This approach requires rigorous representations of the source and the wave propagation effect. We utilize a kinematic rupture model to represent the source and both 1D and 3D velocity models for the crustal structure. Anelastic attenuation is incorporated in terms of material quality factor Q, using empirical relations Q S =50 Vs and Q P =2Q S . To achieve realistic ground motion up to
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The Stochastic Finite Fault Modeling Based on a Dynamic Corner Frequency Simulating of Strong Ground Motion for Earthquake Scenario of North Tabriz Fault

The Stochastic Finite Fault Modeling Based on a Dynamic Corner Frequency Simulating of Strong Ground Motion for Earthquake Scenario of North Tabriz Fault

Strong ground motion is a physical complex process that includes three stages: earthquake waves are partial of strain energy released from fault, which is affiliated to source affect. Then the waves circulate the whole of earth crust, this phenomenon is called as route affect. And finally they are changed across shallow layers until they reach to the surface, which is called as site affect. This is illustrated in Figure 1.

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